Subject: Re: -current broken due to kernfs changes
To: Manuel Bouyer <bouyer@antioche.lip6.fr>
From: Chuck Silvers <chuq@chuq.com>
List: port-xen
Date: 05/23/2005 09:58:06
On Mon, May 23, 2005 at 06:43:32PM +0200, Manuel Bouyer wrote:
> On Mon, May 23, 2005 at 06:01:23PM +0200, Juan RP wrote:
> > 
> > Hi, I've upgraded my NetBSD/Xen system to a newer -current kernel
> > and Xen 2.0.6, booted fine... when trying to create a domU it failed:
> > 
> > Error: Error creating domain: Failed to map domain control interface
> > 
> > Backing out this change seems to work fine again:
> > 
> > Module Name:	src
> > Committed By:	chs
> > Date:		Fri May 20 13:16:54 UTC 2005
> > 
> > Modified Files:
> > 	src/sys/miscfs/kernfs: kernfs.h kernfs_vnops.c
> > 
> > Log Message:
> > kernfs does not support mmap(), remove code that pretends that it does.
> > 
> > Please fix kernfs again, thanks.
> 
> I'm not sure why this change would cause this problem. xend won't mmap a file
> in /kern, it will mmap anonymous memory and use it in a ioctl().
> 
> Chuck, any idea why this would cause xend to fail ? Do some kernfs code
> need to be updated following your change ?

the only effect of this change is that mmap() of kernfs files now fails,
instead of reporting success and then failing later page-faults on those
mappings.  I don't see how this could cause problems for xend.

could we get a ktrace dump of the xend problem?

-Chuck